This application is a national stage of PCT International Application No. PCT/EP2008/010008, filed Nov. 26, 2008, which claims priority under 35 U.S.C. §119 to German Patent Application No. 10 2007 061 208.9, filed Dec. 19, 2007, the entire disclosure of which is herein expressly incorporated by reference.
The invention relates to a roof structure for the body of a motor vehicle with front roof pillars that are connected to each other by a roof frame element.
A roof structure of this general type is disclosed, for example, in European patent document EP 0 677 002 B1, in which two front roof pillars in the form of A pillars extend upwards to a respective connection region to a roof frame element starting from a front face of the chassis of the motor vehicle. This roof frame element is formed as a roof transverse beam, which extends to the respective roof pillars starting from the respective connection regions. The roof frame element thus represents a conventional front roof transverse beam, which forms a windshield frame together with the front roof pillars and thus delimits the windshield upwardly. The roof frame element or the entire windshield frame is thereby supported to the rear by two roof bows proceeding in the longitudinal vehicle direction, which are spaced laterally from each other. These two roof bows are supported at a rear bracket element, which itself is fastened to a rear front face of the motor vehicle body or the passenger compartment.
It is in particular problematic with such a roof structure that the occupants in the passenger compartment dislocate forward for example during a frontal impact of the motor vehicle. In particular on the front vehicle seats (that is, the driver and front passenger), there is often the problem, in particular with vehicles having a low roof structure, that the forward dislocation of the head caused by the crash can lead to an undesired head contact with the front roof frame element. It is obvious that such a head contact increases the risk of injury enormously with such a collision. A further disadvantage of the given roof structure consists in that the view to the front is also limited.
German patent document DE 967 940 C1 discloses a framework for a vehicle construction of a motor vehicle, which is arranged in the manner of a roll-over cage in the region of the passenger compartment of the motor vehicle. This framework thereby comprises a lower part, on which is placed an upper part. The lower part and the upper part are thereby formed by tube elements, which are arranged on the inside of the actual body or strengthen these in the manner of a roll-over cage. In other words, the individual tube profiles of the lower part or of the upper part lie behind those parts which form the actual structure of the motor vehicle body.
One object of the present invention, therefore, is to create a roof structure and a body of a motor vehicle of the type mentioned above, where the occupants of the passenger compartment are subjected to a risk of injury as low as possible during a forward displacement caused by an accident.
This and other objects and advantages are achieved by the roof structure, according to the invention, in which the roof element in relation to its connecting region to the respective roof pillar is arranged so as to be set back in a center region of the roof structure in the longitudinal vehicle direction. In other words, it is provided according to the invention, in contrast to the state of the art according to European patent document EP 0 677 002 B1, the roof element is not designed as a component extending straight in the transverse vehicle direction; rather, its center region is designed—starting from the respective connecting region to the corresponding roof pillar—so as to be set back. This can for example take place in a V-shaped manner, but it would in principle also be conceivable to use a roof frame element with an arcuate or semi-elliptical contour. As a result, it is achieved hereby that a seat occupant—in particular the driver or the front passenger—are subjected to a lower accident risk during a forward displacement caused by a crash, as a component of the roof frame element is no longer arranged in the evasion region, especially for the head. According to experience, the driver or the passenger are moved to the front in the center of the vehicle and upwards with such a forward dislocation caused by a crash, so that it is achieved by the relocation of the center region of the roof frame element in the longitudinal vehicle direction to the rear, that a contact of the head with the center region of the roof frame element cannot result.
A further advantage of such a set back arrangement of the center region of the roof frame element is that a much larger upward viewing region can be provided in particular for the front seat occupants. A windshield can thus be created, which does not only extend over the front face side but also into the upper region of the vehicle roof. It shall be mentioned thereby that this takes place while maintaining highest safety requirements, that is, the roof pillars are still supported against bending or the like by means of roof element in an optimum manner.
It is a further advantage of the arrangement of the roof frame element according to the invention that a holding system or safety belt system of the seat occupant can be designed in such a manner that a maximum forward dislocation path of the head can be used. In particular force peaks due to the forward dislocation caused by an accident can hereby be reduced considerably or be eliminated.
In a further arrangement of the invention it has additionally been shown to be advantageous if the roof frame element comprises two lateral roof frame parts, which extend from the respective connecting region to the corresponding roof pillar at an angle to each other to the roof center. In other words, it has thus been shown to be advantageous if the two roof frame parts are arranged to each other in an essentially V-shaped manner, as the roof frame element is arranged so as to altogether be set back in a center region and furthermore a simple design of the roof frame element results.
In a further arrangement of the invention, the roof frame element comprises a center roof frame part, via which the two lateral roof frame parts are connected to each other. This center roof frame part preferably extends in the longitudinal vehicle direction in a further arrangement of the invention, so that altogether a Y-shaped roof frame element results. This roof frame element has for example the advantage that the center roof frame part can be supported towards the rear, so that altogether an extremely stiff and stable roof structure results, for example also with a rollover of the motor vehicle.
A particularly favorable support of the center roof frame part of the roof frame element can be created if it is connected to a rear transverse roof element of the roof structure, in particular to a roll-over bar of the body. A center roof frame part can thus altogether be created, by means of which the front lateral roof frame parts can be supported towards the rear in a particular reliable and stable manner.
The center region of the roof frame element or the point where the two lateral front roof frame parts are connected to each other via the center roof frame part, is preferably set back by about one to two thirds, and in particular about the half of the length of the roof structure in the longitudinal vehicle direction. A particularly favorable arrangement of the roof frame element can hereby be created on the one hand with a forward dislocation caused by an accident in particular of the head of the respective seat occupant, and a particularly good view is possible for the seat occupants, in particular the driver.
In a further arrangement of the invention, the two lateral roof frame parts are arranged in an extension of the corresponding roof pillars. A roof structure that can be manufactured easily can be created hereby, in which the lateral roof frame parts and the associated roof pillars are possibly also formed in one part.
A further embodiment of the invention provides that respective roof elements are arranged laterally of the center roof frame part, which are formed in a detachable manner. An alternative vehicle concept can thus be created, for example in the manner of a targa.
It is furthermore advantageous if the side doors of the body in the region of the roof structure extend to the center roof frame part. Side doors can be created hereby, which enable a particularly simple entry and exit into the interior of the motor vehicle. The side doors can thereby possibly proceed into the roof region of the roof structure, that is, at right angles between the respective side wall and the roof region of the roof structure. Hereby, there is possibly also the possibility to design such a motor vehicle with wing doors.
The advantages set out above in connection with the structure according to the invention are valid in the same manner for other embodiments of the invention. This is in particular distinguished in that a front vehicle seat is arranged in the center of the body. In other words, a vehicle concept will be provided with the present body in which only one person, namely the driver, is positioned in the front in the center of the vehicle. This has in particular the advantage that the driver is protected correspondingly during a previously described forward dislocation caused by an accident, in that the center region of the roof frame element is arranged in a correspondingly set back manner. Hereby, not only the previously described reduction of the danger of head injuries results, but furthermore a particularly clear driver position is given by the arrangement of the center region of the roof frame element so as to be set back.
In a further arrangement of the invention it has finally been shown to be advantageous if two rear vehicle seats arranged laterally offset to the front vehicle seat are provided. These vehicle seats also have the particular advantage due to the special design of the roof frame element that the respective seat occupant is subjected to an extremely low risk of injury in particular of his head with a forward dislocation caused by an accident. A corresponding arrangement of the side doors has furthermore the advantage that the that the seat occupants of the rear vehicle seats have an exceptionally good view from the vehicle.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.